This application claims benefit of priority under 35 USC xc2xa7119 to Japanese Patent Application No. 2001-83121, filed on Mar. 22, 2001, the entire contents of which are incorporated by reference herein.
1. Field of the Invention
The present invention relates to a system and method for analyzing baby cries to assume and display a psychological condition of a baby.
2. Description of the Related Art
A baby has no words but can pronounce a voice to express some psychological condition. For example, the baby laughs when it is in a good humor and cries when it has some uncomfortable feeling. The baby intends to appeal some inconvenience with a cry and cries when it feels uncomfortable. Persons involved in baby rearing, such as the mother and a nurse, try to diagnose the cause and eliminate the inconvenience. It is often difficult, however, to diagnose the cause of the uncomfortable feeling from the cry of the baby. As a result, the nurse tends to suffer from rearing stresses.
The present invention has been made in consideration of such the situations and accordingly has an object to provide a system for analyzing baby cries capable of diagnosing a cause of cry of a baby based on a cry from the baby.
The present invention provides a system for analyzing baby cries, which comprises audio analysis means for receiving an audio signal of a baby, performing waveform analysis (such as a frequency analysis, and an envelope shape analysis of a waveform) to the audio signal and computing a characteristic quantity based on a result (such as a frequency spectrum and an envelope shape) from the waveform analysis of the audio signal; cause-of-cry assumption means for assuming a cause of cry of the baby based on the characteristic quantity computed at the audio-analysis means; and display means for displaying the cause of cry assumed by the cause-of-cry assumption means.
The inventor performed frequency analysis to audio signals collected from a crying baby when it is painful (immediately after an injection), hungry (before feeding milk or baby food) and sleepy (after a meal before getting to sleep). As a result, it was confirmed that waveforms of the audio signals, such as characteristic quantities based on frequency spectrums, have different patterns respectively in the times of pain, hunger and sleep. The present invention stands on this foot.
According to the present invention, an audio signal of a crying baby is subjected to waveform analysis to assume a cause of cry of the baby from the characteristic quantity based on the result of the waveform analysis and the assumed result is displayed. Therefore, the cause of cry of the baby can be precisely indicated to a nurse who rears the baby, thereby aiding the nurse to reduce a rearing load.
If the result of the waveform analysis is a frequency spectrum, the characteristic quantity based on the frequency spectrum may employ, after clipping one breath-length of audio signal from the audio signal of the baby, at least one of: N frequency spectrums computed for each of N different small zones on the clipped one breath-length of audio signal (N denotes an arbitrary natural number); distributed values at respective frequency bands; cepstrums with respect to the frequency spectrums; and periodic peak positions in the frequency spectrums.
The cause-of-cry assumption means may assume the cause of cry based on the presence/absence of periodicity in each band in the frequency spectrum of the audio signal and a frequency band with periodicity. Specifically, the cause-of-cry assumption means may assume the cause of cry as: xe2x80x9chungryxe2x80x9d when the frequency spectrum of the audio signal has periodicity continuously from a low frequency band to a high frequency band; xe2x80x9csleepyxe2x80x9d when the frequency spectrum of the audio signal has periodicity continuously within a low frequency band; and xe2x80x9cpainfulxe2x80x9d when the frequency spectrum of the audio signal has no periodicity or a period thereof varies in time.
The present invention also provides a method of analyzing baby cries, which comprises receiving an audio signal of a baby; performing waveform analysis to the audio signal and computing a characteristic quantity based on a result from the waveform analysis of the audio signal; and
assuming a cause of cry of the baby based on the computed characteristic quantity.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof.